Decapod :: Decapod (n.) A crustacean with ten feet or legs, as a crab; one of the Decapoda. Also used adjectively..
Decapoda :: Decapoda (n. pl.) The order of Crustacea which includes the shrimps, lobsters, crabs, etc..
Decapoda :: Decapoda (n. pl.) A division of the dibranchiate cephalopods including the cuttlefishes and squids. See Decacera.